For that specific comparison between the 70-200 F2.8LII on 7d and 5dMkII, I'm pretty confident it reflects a difference in the camera sensor or other conditions... (Heat, light etc - but they try to control those)

Remember the lens doesn't throw light any differently onto the sensor irrespective of the camera it's mounted to. If someone uses an adaptor to mount it to a Nikon, the lens is doing the same job optically... These measurements are a combination of lens and camera.

joker97: if you say it's all controlled and you accept the tests then L no great improvement on non L for cropped frame ... are there any other tests that show otherwise?

It's not the point. If you'd like to believe Non-L lenses are pretty much as good as L lenses on cropped bodies, go right ahead. I firmly believe that's false but I'm losing interest in whether others hold that belief.

All that matters is that you are happy with the results your lenses produce. If you're happy with an EFs lens (and there's often NO REASON not to be) then great.

I personally have used non-L and off brand lenses at every focal length and focal length range I use, and in every case (except for a Sigma 15MM F2.8EX Fisheye and a Tamron 90mm F2.8 Macro) I have ended up with the Canon L series lenses because they are better. I also shoot on the mid crop 1d series, but also shot on a 30d for a while with my 24-70 and 70-200 F2.8L lenses. The shots from the 30d and the 1d series (I used 2 cameras at the same time quite a lot) were indistinguishable.

Just to be argumentative, if comparing like MP then the crop factor does change things slightly, as what you find is that you start to push the refractive capabilities of the glass as you're driving more pixels per square mm of glass. On a full frame body more of the lenses area is used, where as with a cropped sensor the outer edges of the glass is not used at all.

I probably haven't explained this well but I remember dpreview talking about this when they compared the Canon 70-200mm F2.8L IS mk1 vs the 70-200mm F2.8L IS mk II.

It's also why Hasselblad and Mamiya cameras can get fantastic results using rather average glass as the sensor size puts less strain on lens quality.

Having said all that, there is more to the story obviously and other things matter too, my Canon EF 200mm F2.8L prime was sharper on my 400D than on my 40D, simply because the body + lens combo had not been calibrated correctly on the 40D and there is no in camera adjustment.

Late last year I upgraded from a five megapixel long zoom lens point and shoot camera to a DSLR. I aganized for quite a while over the same question about what lens to get.

Back in the dark ages when one used 35mm film, I had a SLR with a 28mm to 80mm zoom and a 70mm to 230mm zoom. Both lens were good quaility(Pentax) and produced good results. But....... I travel a bit and always had to cart around the two lenses.Weight while you are on holiday is a pain! Also I found that the change over point in focal length 70-80 mm was the sweet spot that I use a lot to take photos.One or the other of the lenses was never the right one on the body for every shot. So..... the decision I made was that this time I would buy one lens for everything.

I bought a body and an 18mm to 105mm zoom. I wanted to get the best quaility I could afford and considered the 18 to 135 and also an 18 to 200 but went for the shorter focal length lens on the advice that it produced the sharpest results.

I have been on two trips now with this camera and I have been extremely happy with my choice. It has proformed well and on 99% of the time the 105mm tele end of the range has been long enough. Last trip I did a bit of street scape and general scenic touristy stuff with no thoughts as to wishing I had a longer lens.That was over 600 photos in six days. Obviously a wild life safari would require a lot longer lens but for general purpose i'm happy.

If you are spending money on a good brand of body like Canon,I personaly would stick to the Canon brand of lenes. Years ago,I tried out several non camera brand lenses but the results did not come up to what I was acustomed to with the Camera brand makes.Things may have changed by now but for resale in future I think a matching set would be better.

I tend to walk a lot on holiday and carry a camera in a shoulder bag along with all the other stuff that one takes on holiday so lightness is quite a consideration.Compared with a point and shoot type,a DSLR and lens are not light,mine is a Nikon 5100/18 to 105mm combo so thats one of the main reasons for having one multi purpose lens.

Well I got the Canon 600D plus 3 lenses for $1250 as it was a good deal and I figured they would be good to learn with

I have the Canon EF 50/1.8 II, the Canon EF-S 18-55/3.5-5.6 IS and the Canon EF-S 55-250/4.0-5.6 IS

In addition, a very kind individual has offered to send me his 18-55 kit lens for the cost of postage.

I also got a whole bunch of accessories including a case, spare batteries, memory cards, cleaning kit, remote shutter button, etc for the best prices I could find (and prices certainly vary!) Haven't decided on a tripod yet and I am currently using my time to RTFM :)

Now I could sell my 3 new unused kit lenses (cheapest price you could buy all 3 individually on Pricespy is $665+) plus a couple hundred bucks and get a "'nice" lens for travelling and still have the standard 18-55 kit lens or I could keep them all... Looking at Trademe I see I'm not the only one with this train of thought

Typical that I now have the camera and some lenses and still don't know exactly what to do :) If I wasn't going on this trip (which has already cost a load of $$$) I'd just stick to learning on the kit lenses for a while but I'm not too keen on lugging them all around the world... The camera bag I got is fairly big (fits camera + 2x lenses + accessories), would anyone suggest I also get a smaller one that just fits the camera plus one lens & a battery or 2 for when I'm out hiking etc? Wont be doing that much of it but it would help when I am and generic bags can be had cheap

Ive gone from having DSLR to a Lumix like you had for ease of use. Im reasonably happy. Now you have your kit go out and get familiar with it before you go. A few years ago I went to Aussie with a new kit and found it challenging at times to come to grips with it.

Well I got the Canon 600D plus 3 lenses for $1250 as it was a good deal and I figured they would be good to learn with

I have the Canon EF 50/1.8 II, the Canon EF-S 18-55/3.5-5.6 IS and the Canon EF-S 55-250/4.0-5.6 IS

In addition, a very kind individual has offered to send me his 18-55 kit lens for the cost of postage.

I also got a whole bunch of accessories including a case, spare batteries, memory cards, cleaning kit, remote shutter button, etc for the best prices I could find (and prices certainly vary!) Haven't decided on a tripod yet and I am currently using my time to RTFM :)

Now I could sell my 3 new unused kit lenses (cheapest price you could buy all 3 individually on Pricespy is $665+) plus a couple hundred bucks and get a "'nice" lens for travelling and still have the standard 18-55 kit lens or I could keep them all... Looking at Trademe I see I'm not the only one with this train of thought

Typical that I now have the camera and some lenses and still don't know exactly what to do :) If I wasn't going on this trip (which has already cost a load of $$$) I'd just stick to learning on the kit lenses for a while but I'm not too keen on lugging them all around the world... The camera bag I got is fairly big (fits camera + 2x lenses + accessories), would anyone suggest I also get a smaller one that just fits the camera plus one lens & a battery or 2 for when I'm out hiking etc? Wont be doing that much of it but it would help when I am and generic bags can be had cheap

Where'd you get the camera deal from? Cheapest I could see was for the last two lenses at $1,129. So $120 for the other lens seems like an OK deal. I guess it's parallel imported, not covered by Canon NZ. Not worried about that?

Well I got the Canon 600D plus 3 lenses for $1250 as it was a good deal and I figured they would be good to learn with

I have the Canon EF 50/1.8 II, the Canon EF-S 18-55/3.5-5.6 IS and the Canon EF-S 55-250/4.0-5.6 IS

In addition, a very kind individual has offered to send me his 18-55 kit lens for the cost of postage.

I also got a whole bunch of accessories including a case, spare batteries, memory cards, cleaning kit, remote shutter button, etc for the best prices I could find (and prices certainly vary!) Haven't decided on a tripod yet and I am currently using my time to RTFM :)

Now I could sell my 3 new unused kit lenses (cheapest price you could buy all 3 individually on Pricespy is $665+) plus a couple hundred bucks and get a "'nice" lens for travelling and still have the standard 18-55 kit lens or I could keep them all... Looking at Trademe I see I'm not the only one with this train of thought

Typical that I now have the camera and some lenses and still don't know exactly what to do :) If I wasn't going on this trip (which has already cost a load of $$$) I'd just stick to learning on the kit lenses for a while but I'm not too keen on lugging them all around the world... The camera bag I got is fairly big (fits camera + 2x lenses + accessories), would anyone suggest I also get a smaller one that just fits the camera plus one lens & a battery or 2 for when I'm out hiking etc? Wont be doing that much of it but it would help when I am and generic bags can be had cheap

Where'd you get the camera deal from? Cheapest I could see was for the last two lenses at $1,129. So $120 for the other lens seems like an OK deal. I guess it's parallel imported, not covered by Canon NZ. Not worried about that?

I got it from Expert Infotech which is the same place that does the cheapest 2 lens kit. List price for the tri-lens kit was $1289 and I talked him down to $1259. Came standard with a 1 year warranty covered by Expert Infotech and I bought an extra 2 years extended service plan for $122. I don't usually buy extended warranties but figured I would this time as I doubt they're cheap to fix if something major goes wrong and in 3 years I'm sure I'll be ready to upgrade the body anyway

in general you tend to upgrade your lens, as it's the main thing to get good pictures, after composition ... but who knows what gimmick would be invented in 3 years, so yeah you could want that yet unimagined feature